North Carolina Forester Registration Examination
Practice Test (150 Questions with Answers and
Explanations)
Questions 1–10: Mensuration & Inventory
1. A sawlog is 16 feet long with a small-end diameter inside bark (DIB) of 14
inches. Using the Scribner rule, the board foot volume is closest to which
value in a standard log table?
A. 80 board feet
B. 100 board feet
C. 120 board feet
D. 140 board feet
For a 16-foot log with a 14-inch small-end DIB, standard Scribner tables
commonly report about 100 board feet, making that the best estimate for typical
exam purposes.
2. A circular sample plot has a radius of 37.2 feet. Approximately how many
such plots are needed to equal one acre?
A. 5
B. 10
, C. 15
D. 20
Plot area is πr2\pi r^2πr2 with r = 37.2 ft, giving about 4,350 square feet; one
acre is 43,560 square feet, so 43,560 ÷ 4,350 ≈ 10 plots per acre.
3. A forester uses a 10 BAF prism for variable-radius sampling. A borderline
tree has a DBH of 14 inches. Which action is most appropriate?
A. Automatically count it
B. Automatically exclude it
C. Measure the tree’s distance and compare to the limiting distance
D. Use a different BAF prism
Borderline trees require checking the actual distance against the calculated
limiting distance for that DBH and BAF to determine if the tree is “in” or “out.”
4. A tree has two 16-foot logs and a merchantable top of 8 feet. If the form
class is assumed constant, what primary effect does including the 8-foot
top have on stand volume estimates?
A. It has no effect
B. It increases total volume slightly but consistently
C. It doubles total volume
D. It reduces total volume
Adding a short merchantable top increases total merchantable volume by a
smaller increment per tree, but consistently across the stand, slightly raising
volume estimates.
, 5. A forester measures a stand basal area (BA) of 120 ft²/acre. The average
DBH is 12 inches. Roughly how many trees per acre does this correspond
to?
A. 100 trees/acre
B. 150 trees/acre
C. 200 trees/acre
D. 300 trees/acre
For 12-inch DBH trees, 120 ft²/acre of basal area corresponds approximately to
about 200 trees per acre using BA = 0.005454 × DBH² × TPA, rearranged to solve
for trees per acre.
6. A stand has a quadratic mean diameter (QMD) of 10 inches and 250 trees
per acre. If 50 small trees are removed uniformly, what happens to QMD?
A. It stays the same
B. It decreases
C. It increases
D. It doubles
Removing smaller trees reduces the influence of small diameters on the quadratic
mean, so the QMD increases as larger trees become more dominant in the
diameter distribution.
7. A forester wants to estimate stand volume growth. Which combination of
measurements is most appropriate?
A. Height only, once per year
B. Diameter, height, and survival measured on permanent plots over time
, C. Crown width only on temporary plots
D. Soil depth and texture only
Growth estimation requires repeated measurements of diameter, height, and tree
survival on permanent plots to quantify volume change over time.
8. Using a clinometer, a forester stands 66 feet from a tree and records a top
reading of +60 percent and a base reading of −10 percent. What is the total
tree height?
A. 30 feet
B. 46 feet
C. 56 feet
D. 66 feet
Height is (top reading − base reading) × distance ÷ 100 = (60 − (−10)) × 66 ÷ 100 =
70 × 0.66 ≈ 46 feet.
9. A stand table shows most trees in smaller diameter classes with few large
trees. Which stand structure best describes this?
A. Even-aged with normal bell-shaped distribution
B. Uneven-aged with reverse-J diameter distribution
C. Two-aged stand with bimodal distribution
D. Purely pole-sized stand only
Many small trees with progressively fewer large trees is characteristic of an
uneven-aged stand with a reverse-J diameter distribution.
10.A cruise uses fixed-radius plots on a rectangular grid. Which statement
about sampling error is most accurate?
Practice Test (150 Questions with Answers and
Explanations)
Questions 1–10: Mensuration & Inventory
1. A sawlog is 16 feet long with a small-end diameter inside bark (DIB) of 14
inches. Using the Scribner rule, the board foot volume is closest to which
value in a standard log table?
A. 80 board feet
B. 100 board feet
C. 120 board feet
D. 140 board feet
For a 16-foot log with a 14-inch small-end DIB, standard Scribner tables
commonly report about 100 board feet, making that the best estimate for typical
exam purposes.
2. A circular sample plot has a radius of 37.2 feet. Approximately how many
such plots are needed to equal one acre?
A. 5
B. 10
, C. 15
D. 20
Plot area is πr2\pi r^2πr2 with r = 37.2 ft, giving about 4,350 square feet; one
acre is 43,560 square feet, so 43,560 ÷ 4,350 ≈ 10 plots per acre.
3. A forester uses a 10 BAF prism for variable-radius sampling. A borderline
tree has a DBH of 14 inches. Which action is most appropriate?
A. Automatically count it
B. Automatically exclude it
C. Measure the tree’s distance and compare to the limiting distance
D. Use a different BAF prism
Borderline trees require checking the actual distance against the calculated
limiting distance for that DBH and BAF to determine if the tree is “in” or “out.”
4. A tree has two 16-foot logs and a merchantable top of 8 feet. If the form
class is assumed constant, what primary effect does including the 8-foot
top have on stand volume estimates?
A. It has no effect
B. It increases total volume slightly but consistently
C. It doubles total volume
D. It reduces total volume
Adding a short merchantable top increases total merchantable volume by a
smaller increment per tree, but consistently across the stand, slightly raising
volume estimates.
, 5. A forester measures a stand basal area (BA) of 120 ft²/acre. The average
DBH is 12 inches. Roughly how many trees per acre does this correspond
to?
A. 100 trees/acre
B. 150 trees/acre
C. 200 trees/acre
D. 300 trees/acre
For 12-inch DBH trees, 120 ft²/acre of basal area corresponds approximately to
about 200 trees per acre using BA = 0.005454 × DBH² × TPA, rearranged to solve
for trees per acre.
6. A stand has a quadratic mean diameter (QMD) of 10 inches and 250 trees
per acre. If 50 small trees are removed uniformly, what happens to QMD?
A. It stays the same
B. It decreases
C. It increases
D. It doubles
Removing smaller trees reduces the influence of small diameters on the quadratic
mean, so the QMD increases as larger trees become more dominant in the
diameter distribution.
7. A forester wants to estimate stand volume growth. Which combination of
measurements is most appropriate?
A. Height only, once per year
B. Diameter, height, and survival measured on permanent plots over time
, C. Crown width only on temporary plots
D. Soil depth and texture only
Growth estimation requires repeated measurements of diameter, height, and tree
survival on permanent plots to quantify volume change over time.
8. Using a clinometer, a forester stands 66 feet from a tree and records a top
reading of +60 percent and a base reading of −10 percent. What is the total
tree height?
A. 30 feet
B. 46 feet
C. 56 feet
D. 66 feet
Height is (top reading − base reading) × distance ÷ 100 = (60 − (−10)) × 66 ÷ 100 =
70 × 0.66 ≈ 46 feet.
9. A stand table shows most trees in smaller diameter classes with few large
trees. Which stand structure best describes this?
A. Even-aged with normal bell-shaped distribution
B. Uneven-aged with reverse-J diameter distribution
C. Two-aged stand with bimodal distribution
D. Purely pole-sized stand only
Many small trees with progressively fewer large trees is characteristic of an
uneven-aged stand with a reverse-J diameter distribution.
10.A cruise uses fixed-radius plots on a rectangular grid. Which statement
about sampling error is most accurate?
